gmp: fix to use host g++ and remove '--target' configure option at toolchain stage

base/gmp/gmp.conf

@@ -2,7 +2,7 @@
 # This copyright note is auto-generated by ./scripts/Create-CopyPatch.
 #
 # Filename: package/.../gmp/gmp.conf
-# Copyright (C) 2007 The OpenSDE Project
+# Copyright (C) 2007 - 2009 The OpenSDE Project
 # Copyright (C) 2004 - 2006 The T2 SDE Project
 #
 # More information can be found in the files COPYING and README.
@@ -13,6 +13,12 @@
 # GNU General Public License can be found in the file COPYING.
 # --- SDE-COPYRIGHT-NOTE-END ---
 
+# use host g++ and remove '--target' configure option at toolchain stage
+if atstage toolchain; then
+	export CXX=g++
+	var_remove_regex confopt ' ' '--target=.*'
+fi
+
 if atstage native; then
 	var_append confopt ' ' "--enable-cxx"
 fi